The present invention relates to video/image decoding, and more particularly, to an apparatus and method for decoding region of interest (ROI) regions in an image.
The conventional video/image coding standards generally adopt a block based coding technique to exploit spatial and temporal redundancy. For example, the basic approach is to perform intra prediction/inter prediction on each block, transform residues of each block, and perform quantization and entropy encoding. Besides, a reconstructed frame is generated to provide reference pixel data used for coding blocks in following frames. For certain video/image coding standards, in-loop filter(s) may be used for enhancing the image quality of the reconstructed frame. A video/image decoder is used to perform an inverse operation of a video/image encoding operation performed by a video/image encoder.
A full image may be divided into multiple regions, and these regions may be coded as sub-images, sub-frames, or tiles. Some of the regions in an image may be categorized as region of interest (ROI) regions, while the rest of the regions in the same image may be categorized as non-ROI regions. For certain applications, only the ROI regions in an image are needed to be decoded at a decoder side. Thus, there is a need for an innovative video/image decoding design which is capable of decoding ROI regions in an efficient way.